To show your readers that you have taken the care to create an
interoperable Web page, you may display this icon on any page
that validates. Here is the HTML you could use to add this icon
to your Web page:

If you like, you can download a copy of this image (in PNG or GIF
format) to keep in your local web directory, and change the HTML fragment
above to reference your local image rather than the one on this server.